T X 

.13 









Book .T& 



'i'N • HSnOYUAS 

SU3MVH 

soua ouoiAvo 



i NUTS AND THEIR USES AS EOOl). 



r.y 



M. E. JAFFA. 

Aaslxidnl /V(;^•.s^s■()(• (if Xulritioii, I'ldvirsili/ of ( 'alfoniiii. 



[Reprint fkcim Ykakho<ik m- ]>i;i'aktment of Ai:kici'lti.'rk for lilOt!.] 



4880—07 



WASHINGTON : (iO»EHrn*E^T PRINTING OFFICE : 1907 



CONTENTS. 



,0^ 



V' 



Iiitro(Uii-ti(jn 295 

De.si-rijitioii i)t' nut.-' 296 

Th(' riavor of nuts 29S 

Composition of nuts 298 

Digestibility of nuts 301 

Plate of nuts in the diet 1 303 

Nut butters 304 

Nut pastes anil luit jireserves 305 

Nut Hours and meals 306 

Xnt candies 307 

Nut coffees 308 

Green mits 308 

Nut oils and oil-cake meals 309 

Pecuniary ec momy of nuts 309 

Handliuir and marketing; nuts 311 

Suniuiarv 312 



ILLUSTRATIONS. 



ri.ATK. 



Tncp. 



Plate XV. Fij:. 1. —California Indians imundin;; acorn iiu-al fur fodd. 

Fig. 2. — Califnrnia Indian leaching acorns fur food 306 

TEXT EIOIISE. 

Fk;. 8. I'lrccntau'c ciiMipnsitiDn nl an oily nut ( walnut i and a starcliy mil 

( cliesi nut ) 300 

SEP ^8 1907 

•■'. : U. vt U. 



M IS AM) THEIR T SES AS FOOD. 

' Hy M. E. Jama, 

As.iistant I'mfiasi'i- of XiilriHo)i. I'liinrxily of (iilifoniiii. 

IN'I'KODUCTION. 

Tlic constantly increusini; consumption of nuts tlirouijliout (lie 
United States augurs well for a better appreciation of their food 
value. The time when nuts were considered merely as a luxury, or 
as sometiiing to be eaten out of iiand at odd times, is rapidly ])assini; 
away. In earlier days the native hickories, l)utternuts, walnuts, chest- 
nuts, and many other nuts found in the United States were to be liad 
in country regions for the gathering and wer(> of no commercial inij)or- 
tance. On the other hand, the English wahuits (to give tiiem their 
most connnon name), almonds, cocoanuts, elc, l)rought from other 
countries, were relatively expensive luxuries. Conditions have mate- 
rially changed and our principal native nuts are now staple market 
conunodities and bring good j)rices. At the same time, owing (o 
changes in market conditions, the jirice of the imported nuts has 
drop])ed so that they are well within the reach of the majority. 

Some nuts, like the native hazelnut and beechnut, have i)ractically 
no conmercial value and, though palatable, are almost never offered 
for sale, doubtless because they are so small an<l (hfiicult to gather in 
((uantity. The chincpiapin, a small nut allied to the chestnut, finds 
a limited sale in southern cities, but is .seldom seen in other markets. 

From available statistics it appears that in 1905 the total ((uantit}' 
of almonds, cocoanuts, Brazil nuts, tilberts, jwanuts, walnuts, and other 
nuts, shelled and unshelled, imported into the United States was, in 
round numliers, SO, 2:5s, ()()() poumls, with a value of .f(i,i;5S,()l)(). In 
lOor) the total almond cro]) in California readied 4, 200, ()()() ])ounds 
and the walnut crop 12, SOI), 000 jiounds. The richest yield of |)eanuts 
was re]iorted from the Soutiiern States, ciiii'dy \'irginia, Cieorgia, and 
Tennessee, and amount(>d to 22."i,000,()00 |)ounds. 

The total (piantity of home-grown nuts, including both native an<l 
cultivated varieties, nuist far exceed the ((uantities imported, but in 
th(» natui'e of the case no estimates of the total (juantities gathered 
and eaten are ])rocurable. When we consider tiie constantly increasing 
demand for nuts and the large rjuantity wliicli we imjiort the ])ossi- 
l)ilities of the industry for the American nut grower are obvious. 

As the use of nuts has increa.sed, nniny persons have turned their 
attention to the growing of native and foreign nuts on a commercial 

295 



296 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

scale. Tlii.s work has been furwartled by the Department of Aj^ri- 
culture, through the Bureau of Plant Industry, and by the Califor- 
nia, Florida, Michigan, and other agricultural experiment stations. 
With nuts, as with other crops, it has been found that, by selection 
and l)reeding, improved varieties are obtainable, of larger size, bet- 
ter flavor, thinner shells, or other desirable characteristics. The 
increased demand for nuts is due in the main to two causes, namely, 
a better appreciation of their appetizing cpialities and the numerous 
ways in which they forni a palatable addition to tiie diet of the 
average family, and, secondly, to -their use by the vegetarians and 
persons of similar belief — a group small in proportion to the total 
])opulation, but still fairly large numerically — who use nuts, and 
more particularly the peanut, as a substitute for meat and other 
nitrogenous and fatty foods. 

Many sjiecial nut foods, such as inaltetl nuts, meat substitutes, etc., 
have been devised and extensively advertised by the manufacturers 
for general use in the diet and for the special needs of vegetarians and 
fruitarians. It is said tiuit some of these American nut jiroducts con- 
fain soy l)eans, l)ut a])])arently tiie peanut plays a very important part 
in their composition. In either case, since the peanut, like the soy 
Ijean, is a legume, these preparations might more properly be compared 
with the bean chee.se and other soy-bean jmxlucts so much used in 
China, Jajxm, and other eastern countries than with such nuts as 
the walnut, almond, or cocoanut. 

DESCRIPTION OF XUT8. 

The term ''nut" is not a defmite one Ijotanically speaking, but is 
ap])lied indiscriminately to a variety of certain fruits or parts of 
friuts and implies a more or less luu'd, woody covering surrounding a 
meat or kernel. The most diverse plant grou]xs contribute to our nut 
8U])ply, many of the nuts being the product of our beech, chestnut, 
walnut, and other deciduous trees and bushes, some of pines and 
tropical palms, and others, like tlie peanut ami pistache or pistachio, 
being the fruit, respectively, of a vine-like plant and a small tree, 
both Ijelonging to tlie family of legumes. Still another, the water 
chestnut, is supplied l)y a water ])lant. 

Most of the native and foreign nuts which we use are too familiar 
to need description. Several, however, are not so generally known. 

Pinenuts, which grow in the cones of a number of varieties of native 
and foreign pines, are now fairly common in our markets. The 
'Indians have always known and appreciated them and have passed 
on their knowledge to the white race. Then, too, many immigrants 
wlu) came to this country knew the pinenut, for it has long been much 
eaten in Italy and t>ther parts of southern Europe, where there are a 
luunber of nut-yielding jiines. The small, rather pointed white nuts 



NfTS AXD THEIll USES AS FOOD. 207 

are usually marketod siielled, hut as (hoywnnv are cuA-ertMl willi a more 
or less hard, wnody shell. The ])istaehe iiu( (now i^'ruwii in ('ahf(irnia) 
has long l)een used and is ])rized hy eonfectioners for its delicate 
flavor and attractive green color, yet it is by no means common. 
The nuts are small, not imlike a liean in size and shape, tliougli more 
pointed, and l)efore marketing are I'reed from the ptuls in which they 
grow. The indiAidual nuts are covered with a gray or ]iur]dish skin, 
and are blanched liefore they are useil. 

The so-called lichi luit, which is really a dried fruit .surrounded l)y 
a nut-like .sliell and not unlike a raisin in flavor, is a favorite in 
China and lias ])econie (|uite common in this country. The ginkgo 
nut, the fruit of an ornamental tree (|uile widely grown in the United 
States and .sometimes called the uiaideidiair tree from the shape of 
the leaves, and which fruits abundantly in some regions, is seldom 
eaten except by the Chinese, who gather it whenever possible. The 
small, roundish, oval, thin-shelled luit is siu-rounded l)y a very acrid, 
l^ad-smelling pulp, the whole fruit being not unlike a gi'cen damson 
plum in size and a]>i>earance. In Cliina, Korea, and other parts of 
the Orient this mit is nuich used as a food, and, so far as can he 
learned, is always cooked in some w.iy. ''' Roasted like a, ])e;inut. il is 
palatable. The ginkgo nuts are on sale in the Chinese sho])s in San 
Fi'ancisco and (h)ubtless in otiier cities, and were studied at the Cali- 
fornia experiment station some years ago, togethiM' with other Chinese 
toods. 

'The water chestnut, or horn chestnut ( 7V(/y«; hisiiiiiosa), an aijuatic 
])lant, prinluces a seeil or "nut" which somewhat resembles two 
curved horns united in one, the kei'ucd of which is largely used as a 
food by the inhabitants of Asiatic countries. This so-c'alled mit 
is also on sale in the United States, but chiefly in Chin(>se shops. 
An<ither water ]>lant (Ehorliaris fiilMrasa) is also known as the 
water chestnut , but in this case it is the corm or bulb that is eaten. It 
is not unlike a chestnut in shape, and has a tough, brown skin. This 
is grown in Asia, l)ut is im])orte(l by the Chinese in this coimtry. A 
three-cornered pointed nut or seed, the ]»if of tlie Chinese olive 
{(Aniarhiin sp.), is also on sal(> at Chinese sho]>s in the United States. 
The kernels are oily but jialatable, and are used in Java for making 
a nut milk much thoughl of for infant feeding. 

The chufa, nut grass, or earth almond is a small tuberous root of a 
.sinlgelike plant and ])erhaps should lie classed with the vegetables 
rather than with nuts. It is not common, though sometimes eaten. 

From time to time new luits make their ajiiiearaiice on the market 
as some nut prizeil locally becomes known to the trade. A nut which 
seems to be growing in ])opularity, though still uncommon, is the Pai- 
adise nut of South America, which resembles a Brazil nut in ajipear- 
ance anil flavor. Still less conmion is the South African cream nut, 



298 YEARBOOK OF THE DEPARTMENT OF AGKK'ULTURE. 

thouiili it is sometimes shipped to this country. The clioicest member 
of tlie Brazil-nut group is the true "butternut" of the Tropics, which 
is very seldom found outside that i-egion. Its flavor is verj' delicate 
and delicious, but it does not keej) well; and even if it would bear ship- 
ment successfully, the available supply is at present very small. The 
cashew nut of tro])ical regions, wliich many consider one of the most 
delicious nuts grown, has long been known, but has never become com- 
mon. It is sold to some extent and brings high prices. Tliis nut is 
roastetl before it is eaten, as the raw nut contains poisonous properties 
which are readily ilestroyed by heat. 

The oval, flat, and rather large seeds of a luimpkin-like fruit, tabe- 
l)uia (Telfairia pedata), from Zanzibar, which lias been grown in a 
limited way at the Porto Rico exjteriment station, are roastetl and 
eaten like a nut. The flavor is oily ami fairly palatable. This sug- 
gests the use in Russia of the raw sunflower seed, which is ricii in oil 
and not unlike some of the common nuts in composition. Theseetls 
arc eaten out of hand at all times and by all classes. 

THE FLAVOR OF Nl'TS. 

The flavor of nuts is very largely de]H>ndent iqx^n the oils wliich 
the}' contain, though in some there are also specific llavorijig bodies. 
The nut oils readily become rancid, the very tli.sagreeable flavor of 
spoiled nuts being due to this property. Some nuts, for instance, the 
chestnut, have a starchy flavor as well as a "nutty" taste. The 
small native nut is much more highly flavored than the large Italian or 
the Japanese chestnut. The almond posses.ses the cyanic-acid flavor, 
which is characteristic of peach pits, plum pits, etc., and this might be 
expected wheTi it is rememljered that the almond is the dried j)it of an 
inedible fruit somewhat resembling the peach in appearance and 
closely relatstl to it botanically. Most almonds are mild navt)i-ed, 
though in the so-called liitter ajmonds the cyanic-aciil yiekling glucosid 
is more abundant. In raw peanuts there is a tleciiled flavor resem- 
bling that of the closely related beans and peas, and to some persons 
this is not im|)alatal)le. In the roasted peanut, which most of us 
prefer to the raw, the flavor is largely dependent uj^on the browned 
oils and stai'ches or other carliohydrates. 

COMPOSITION OF NUTS. 

The composition of nuts and nut products has been studied at a 
nundjer of the agricidtural experiment stations, notably California, 
Maine, and Iowa, and the table on the following page summarizes the 
residts of this work, the American data being su])])lemented in a 
number of cases by the results of European analyses. For purposes 
of comparis(jn several other common food materials are also included. 



NUTS AN'D THEIR USES AS FOOD. 



299 



Aucmiie composition of nats and mil prodii.rlx. 



Kin.l of food. 



/'( 



34. 6B 

;a. 08 



Nuts jind nut products; 

Acorn , $resh 17. 80 

Alinonil 47.00 

Beechnut ; 311. MO 

Brazil nut 49.3.5 

Buttprnut Sfi. 40 

Candle nut 

Che.stnut, frostl l.i. 70 

Chestnut, dry ' 23.40 

1 Torn chestnut nr water chest- 
nut , 

Chufa (earth ahuond) 

Cocoanut , 

Filbert 

Ginlcgo nut (seeds) 

Hickory nut tj2. 20 

Liclii nut 41. 00 

Paradise nut 4.5. 70 

Peanut 27.04 

Pecan ; .50. 10 

Pignolia (shelled) 

Pistachio 

Walnut 

.Vhnond Initter 

Almond paste 

Peainit hutter 

Malted nuts 

Cocoanut candy 

Peanut canily 



Chestnuts, preserved (niarron 
gla.c6), air dried 

Walnuts preserved in sirup, 
air dried 



Cocoanut milk 

Cocoanut. desiccated 

Peanut coffee made from en- 
tire kernel 

Chestnut flour 

Cocoanut flour 

Hazelnut meal 

Other foods for comparison: 

Meat, round steak 

Cheese, cluxldar 

Eggs, boiled 

Wheat flour, high gradi^ 

White bread 

Beans, dried 

Potatoes 

Apples 

Raisins 



58.80 



Edible portion. 



20. 00 
25.00 
10.00 



34.7 
4.9 
li. I) 
4.7 
4.5 
.5.9 

43.4 
ti. 1 

10. (1 
2. 2 

1.3.0 
.5.4 

47.3 
,3.7 

10. 4 
2.3 
7.4 
.3.4 
0. 2 
4.2 
3-. 4 

2. 2 
24.2 

2.1 
2.0 
3.9 
,3.0 

IS. 2 

10.9 
92.7 

3. .5 



Pro- 
tein. 



Fat. 



4,4 
21.4 
21.8 
17.4 
27. 9 
21.4 

ti. 4 
10.7 

10.9 
3. 5 
fi. 6 
10.5 
5.9 
1.5. 4 
2.9 
22.2 
29.8 
12.1 
3.3.9 
22.0 
18.2 
21.7 
13.1 
29. 3 
23. r 
2.4 
10.3 

1.3 

1.3.6 
.4 

0.3 



4.7 
.54.4 
49.9 
05. 
01.2 
01.7 
ti.O 
7.8 



5.1 


27.9 


7.8 


4.6 


14.4 


20.6 


2. 7 


11.7 


05. 5 


19.8 


27.4 


27.7 ': 



43.; 
70.: 
48.: 

.54.; 
00. ■ 
61.; 



20.0 

1.5 

57. 4 

,50. 1 
3.4 
2.1 

lis. 

13.0 
30.8 
10.7 



Carbohy- 
drates.' 



^ugar, \ 

starch, 

etc. 



Prr ,/. 
50. 4 
1.3.8 



4. 


9 


41 


3 


70. 


1 


73 


8 


50 


2 


13 


7 



Crude 
fiber. 



Pent. 

4.2 



1.5 
2.9 

1.4 

10. 5 
8.9 



' I 
11.4 

78.0 

10.2 



14.' 

8.. 



2.4 
3.7 

1.4 



17.1 
43,9 



48. 

4.0 

31.5 

12. 3 I 2. 4 

SO. 8 
45. 9 I 10. 1 

17. S 



12. 


11.4 


1.0 


74.8 


35. 3 


9.2 


1.3 


.52. 


12. 


22. 5 


1.8 


.55. 2 


7S.3 


2. 2 


.1 


IK.O 


84.0 


.4 


.5 


1.3.0 


14.6 


2.6 


3.3 


73.0 



Pir el. 
1.0 



Fuel 

value per 

p»3und. 



CalorU 
1.2 



2.5 


2,895 


3.7 


2,740 


3.3 


3,120 


3.0 


3,370 


3.3 


3,020 


1.4 


1,140 


2.4 


1,S40 



2,0 
2.0 
1.0 
2.4 , 
2.0 
2.1 
1.9 
2 7 
•> o 

Mil 

3.8 

3.1 

1.7 

3. 

1.0 

.5.0 



3.4 
li. 9 



1.1 
4.0 



1.1 
3. 5 
1.0 
.3 
3.4 



1,.540 
2,4:!5 
2.805 
3,100 
941) 
3,345 
1,510 
3,3,S(I 
2,010 
3,300 
2,710 
3,2,50 
3,075 
3,340 
1,9IK) 
2,825 
2, UK) 
2,0(H> 
2.115 

1,,530 

2,780 

155 

3,125 

2,805 
1.7SII 
1,4SII 
3, 1,H5 

9,50 
2,145 

CSfl 
1,0.50 
1,215 
),i;o5 

3.S5 

290 



300 



YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



Refuse, mostly sh(>ll, constitutes a considerable pro])ortion of the 
nuts as purchased, varyino; irreatly with the different kinds. With 
fresh chestnuts the jjroportion is nearly 16 per cent, ])eanuts 27 per 
• •cut, almonds 47 per cent, and butternuts 86 per cent. 

The edilile ])()rtion of nuts, with few exceptions, is very concentrated 
food, containing' little water and much fat. In general, nuts are also 
rich in protein. These ranking highest in this nutrient, the pignolia, 
)i variety of pinenut imported from .Spain, with 33.9 per cent, the pea- 
luit witli 29. S ]3er cent, and the butternut with 27.9 per cent protein, 
.surpass most or<linar}' animal or vegetable foods in this re.spcct. The 
iilmond, beechnut, and pistachio, with 21.4 per cent, 21. S per cent, and 
22.6 per cent, respectively, compare favorably with dried legumes. 
The Brazil nut contains 17.4 per cent protein, the iilbert 16.5 per cent, 
tire walnut IS. 2 per cent, the hickory nut 15.4 per cent, the pinenut 
14.8 per cent, the pecan 12.1 per cent, and the dry chestnut but 10.7 
per cent. The dry acorn, fresh chestnut, and cocoanut, with, respec- 
lively, 6.4, 6.4, and 6.6 ])er cent, are not as rich in protein as ])read. 



WATER 25'^'' 

PROTE/N /66 •>-'' 

FAT 6H% — 

STARCHSUCAR.CTC I3,S°>C^ 
CRUDE F/BER Z6 %- ^ 
ASH l-ffo-^ 




5 9 Jo WATER 
~ 107 % RROTEIN 
- 7.O04 FAT 

-TS % STARCH. SUCARETC 
^21% CRUDE FIBER 
^22% ASH 



WALNUT. CHESTNUT. 

Fir;, s.— PTcentag" mniposi tioii of -.m oily imt (walnut) and a stiirdiy nut (chostnul ). 

Of the nuts here included I lie richest in fat is the pecan, with an 
average of 70.7 per cent, but 7 other varieties — the Brazil nut, butter- 
nut, candlenut, filbert, hickory nut, pinenut, and walnut — contain 
upward of 60 per cent. The almond, cocoanut, and pistachio yield 
between 50 and 60 per cent of this nutrient. The beechnut, peanut, 
and pignolia contain about .'iO per cent. In other words, in 13 of the 
varieties of nuts appearing in tlie foregoing table, half or more of the 
edible portion is fat or oil. 

Only a few of the conunonly used nuts yiekl any notable amounts of 
total carbohydrate matter, t lie dry chestnut, with 73 per cent, rating 
liighest. Beechnuts, ])inenuts, and peanuts have about 18 per cent. 
The quantity of starch found is, with some exceptions, c[uite small, 
ranging from 3 ]5er cent in the l)eechnut to 27 per cent in the chestnut. 

Figure 8 shows in diagrammatic form the percentage composition 
of an oily nut, the walnut, and a starchy nut, the chestnut. 

Nuts are, comparatively speaking, well supplied with mineral mat- 
ter, this constituent in the majority of nuts exceeding 2 per cent. 
The ash of the walnut, almond, etc., is rich in phospluiric acid, and 



NUTS AND THEIR I^SES AS? FOOD. 301 

in this rcpjard compares favorably with that <if cereals. It would 
appear from the data on the digestibility of nuts that the mineral 
matter is as well assimilated as that fron^ nthei' common foods. 

DIGESTIBILITY OF NUTS. 

With (he exception, perhaps, of dried beans an<l cheese, no food 
material has the reputation for indigestibility that has been accorded 
to nuts. Discomfort from them is largely duo to insufficient mastica- 
tion and to the fact that nuts are often eaten when not needed, as after 
a hearty meal or late at night, though it is undoubtedly true that nut 
protein as ordinarity eaten is not so easily or so completely chgested as 
meat protein. A^ery likely the concentration of nuts, with but 3 to 5 
per cent water, as compared with meats containing from 50 to 70 per 
cent water, is a contributing cause. If careful consideration were 
given to this matter and if attention were paid to the proper use of 
nuts and their correct ])lace in the diet, there would be less inifavor- 
able comment on their digestibility. 

The results of investigations carried on with fruit and nut diets at 
tlie California Agricultural Experiment Station aiford tentative con- 
clusions regarding thoroughness of digestion which should be of value 
to those who wish to use nuts as a staple article of food rather than as 
an occasional article of diet. This work has comprised 15 dietary 
studies and about 100 digestion experiments with elderly men, j'oung 
men, women, and cliildren, of whom some liad been vegetarians for 
years, and some had even limited their diet almost exclusively to fruit 
and nuts; others had previously lived on the usual mixed diet. The 
average coefficients of digestibility reported for 28 experiments with 
2 men and 1 woman were: Protein, 90 ])er cent; fat, S5 per cent; 
sugar, starch, etc., 96 i^er cent; crude fiber, 54 per cent: and ash, 68 
per cent, with S6 per cent of the energy available. The correspond- 
ing figures for three experiments with the same sul;)jects in which no 
fruit or nuts were used are: Protein, 94 per cent; fat, 92 per cent; 
sugar, starch, etc., 96 j>cr cent; crude fiber, 49 per cent, with 8S ])er 
cent of the energy available. The latter coefficients agree very closely 
with those in the average of nearly 500 experiments \nth difl'erent 
sorts of mixed tliet, namely: Protein, 92 jjercent; fat, 95 per cent; and 
carbohydrates, 97 percent. In view of tliese facts regarding compo- 
sition and digestibilitjr of their diet, it is evident that nuts must be 
regarded as the main source of protein for the fruitarians. The studies 
with fruitarians have all indicated that nut protein is fairly well assimi- 
latetl ; and that this is true with the average healthy person is well illus- 
trated by an experiment with a university student, who, though en- 
tirely unaccustomed to such fare, gradually changed from an ordinary 
mixed diet to one of fruit and nuts, which he followed for a time with- 
out apparent loss of health or strength. 
4S80— 07 2 



302 YEARBOOK OF THE DEPARTMENT OF AGRICVLTURE. 

It is somewhat difficult to arrive at definite conclusions regarding 
the actual percentage of nut protein digested or assimilated. The 
experimental data obtained at the California station show a range 
of 75 to 82 per cent digestible protein when fruit and nuts were 
eaten together, but the figure for nut protein is doubtless liigher. 
These coefficients were in all probability influenced by the fruit pro- 
tein, wliich has been found to be less digestible than the nut protein. 
The digestibility of protein in 28 experiments with mixed diets, to 
which were added fruit and nuts, averaged 90 per cent. 

As fruits, with the exception of the avocado and olive, jieM only 
a small amount of fat, the fat which is contained in a fruitarian diet 
must be very largely obtained from the nuts. The average coefficients 
of digestibility for this nutrient in 30 experiments with men on a diet 
of fruit and nuts was 86 per cent, and in the 28 experiments just re- 
ferred to it was 85 per cent. These figures are about 10 per cent 
lower than the average coefficient for digestibility of fats in the ordi- 
nary mixed diet. The digestibilitA^ of the carbohydrates in nuts, so 
far as the available data show, is about ecjual to that of the same 
ingredients in other foods. 

So far as can be ascertained no experiments have been made on the 
ease or rapidity of digestion of nuts. In the absence of such data it is 
fair to assume that within reasonable limits the finer the state of 
subdivision of the food material, the easier, the more rapid, and per- 
haps the more nearlj^ complete will be the digestion or assimilation, 
presupi^osing, of course, that the nuts are not eaten in addition to a 
hearty meal. Too much stress can not be laid on the necessity of 
thorough mastication of nuts. This is emphasized by the residts ob- 
tained with one of the subjects at the California station, who ate 
largely of nuts but did not properly masticate his food. The coeffi- 
cients of digestibility of the food were far lower than for other sub- 
jects who chewed their fooil thoroughly. The expeiiments with fruit 
and nut diets in general indicate that nut protein is as easily, even if 
not quite so completely, digested as protein from bread and milk. 

The present discussion refers only to the nuts included in the 
studies at the California station, viz, the almond, Brazil nut, cocoanut, 
peanut, pecan, pignolia, and walnut. It is believed that these are 
typical of the ordinary edible nuts, but further digestion experiments 
are much needed for the purpose of testing some other nuts. 

As regards the work of other investigators, both ^lemmo" and 
Merrill '' report experiments with cooked chestnuts. Memmo's sub- 
ject was a farm lal)orer, 53 years old, working eight hours a day. 
The experiment lasted four days. During the first two the food con- 
sisted exclusively of chestnut products. This was modified during 

a Ann. Inst. Ig. Spcr. Vniv. Roma, n. s., 4 (1894), p. 263. 
6 Maine Sta. Bui. 131, p. 14G. 



NUTS AXD THEIK USES AS FOOD. 303 

the last two days by the addition of herrinii; and cheese. In this 
experiment 75 per cent of the protein, 87 i)er cent of tiie fat, 97 per 
cent of the total carbohytlrates, and S3 ])er cent of the ash were assim- 
ilated. The last figure is high ; the others correspontl to those 
reported for the California experiments with a fruit and nut diet. 

The subjects of Merrill's experiments were two men aged 23 and 3-1 
years, respectivel}-. A mixed diet was used. Each sidiject consum(>d 
daily 300 grams of cooked chestnut flour, whicli furnislied about 20 
per cent of the proteids, 50 per cent <if the fat, nearly 50 per cent of the 
carbohydrates, and not far ft'om -10 per cent of the total fuel value of 
the food. The average digestion coefficients obtained for chestnuts 
with the two subjects were protein 56 per cent, fat 63 per cent, anil 
total carbohydrates 98 per cent, while 89 per cent of the energy was 
available. Memmo also studied a kind of acorn Ijread eaten in Italy, 
and found it was fairly well assimilated, though not very palatable. 
Saiki " found that starch of raw Italian chestnuts was relatively 
indigestible. 

It would appear, then, that, while it is not possible to state the exact 
digestion coefficients for all nuts, enough has been done to indicate 
their high nutritive value and digestibility. 

PLACE OF NUTS IX THE DIET. 

It has been shown liy numerous investigations that nuts are ricli in 
protein and fat and that these nutrients can be fairly well assimilated. 
Nuts being such a concentrated footl, their proper ]>lace in the diet is 
a matter for more careful consideration than is the case with many of 
our ordinary food materials. It must not be forgotten that a certain 
bulkine.ss of the diet is conducive tt) its normal assimilation, anil that 
too concentrated nutriment is often the cause of iligestive disturb- 
ances. It might be expected, then, that nuts ct)uld be most advan- 
tageously used in connection with more bulky foods, such as fruits, 
vegetal)lcs, breads, crackers, etc. Most rationally used, they siiould 
constitute an integral part of the menu rather than supplement an 
already abundant meal. Since nuts are .so concentrated, eating a 
considerable quantity out of hand at odd times will mean an over- 
supply of fooil if a corresponding reduction is not maile in other foods. 
The distress sometimes experienced when nuts are eaten is undoubt- 
edly often tlue to improper mastication or to overindulgence. Tlie 
investigations made at the California station indicate clearly that 
considerable ciuantities of nuts properly eaten do not cause distress. 
There is a popular belief that a little salt with nuts ]>revents the diges- 
tive disturbance resulting from eating them. To most persons, salt 
undoubtedly adds to the palatability of the nuts, but no investiga- 
tions have been found on record which demonstrate any actual 
improvement in tiie digestibility of nuts due to salt. 

a Jour. Biol., 2 (l<K)6i, p. 2.51. 



304 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

Nuts may he readily used as staple articles of diet, as an ingreilient 
in salads and in soups, as a stuffing for poultrj', in the malving of des- 
serts, and in many other ways. Wild turkey stuffed with pecan nuts 
is a dish popular with old Yirgmia cooks, just as goose stuffed with 
chestnuts is prized in Germany. Salted nuts and nuts crystallized 
in sugar are very coimnon accompaniments of other foods. In general, 
the nuts rich in protein and fat should be used in combination with 
carbohj'drate foods, as bread, fruit, green vegetables, etc., while such 
nuts as the chestnut, which do not contain much protein or fat, but are 
rich in carbohj^drates, may be properly combined with meats, milk 
and cream, eggs, and other foods containing protein and fat. 

Smce nuts are relished by most persons, are nutritious, and maj^ be 
readilj^ used by themselves and in various palatable combinations as 
an integral part of the diet, they have a legitimate place in the menu. 
Those who, for anj^ reason, wish to live on vegetable foods and dairy 
products or any form of vegetarian or fruitarian diet will almost 
inevitably look to nuts, particularly such as the peanut, for a con- 
siderable proportion of their total nutritive material. A fruit and 
nut diet may be arranged to furnish sufficient protein, mainlj^ from 
nuts, to satisfy the requirements of the body, but the consensus of 
opinion of well-informed physiologists seems to be that such a diet is 
not generally advisable nor to be recommended for the majorit}" of 
mankind in place of the more usual mixed diet. It should also be 
remembered that numerous experiments have shown that the protein 
from mixed diet has a higher coefficient of digestibility than nut pro- 
tein, wliich indicates that the protein of nuts is the less economically 
utilized by the body. The argument wliich is so often advanced that 
j)rimitive man lived on nuts and fruits exclusively and hence his 
descendants should do so, is not generally accepted. 

The comparatively high price of many of the ecUble nuts, particu- 
larly when shelled, and the difficulty of cracking some varieties — 
like pecans, black walnuts, and hickory nuts — and extracting the 
kernels at home, greatly militate against the freer use of nuts in the 
household. The consimiption of peanuts and Enghsh walnuts is per- 
haps increasing faster than that of some other nuts; but, whatever 
sort is selected, they should, as already noted, form a part of the diet 
and not supplement an already sufficient meal. 

NUT BUTTERS. 

Within the last few years so-called nut butters have been used in 
increasingly large amounts, and at least one variety, namely, peanut 
butter, is made and sold in ton lots. It has already been stated that 
in order to insure the best physiological results from the dietetic use 
of nuts they should be thoroughly ground up by the teeth and that, 
other tilings being equal, the digestion coefficient will vary directly 



NUTS AND TITEtK USES AS FOOD. 305 

with the fmeiipss of division. The nut buttei's, made as they arc 
from the finely ground nuts with or without tiie aikUtion of some 
water, oil, and salt, have a homogeneous consistency not unlike true 
butter, and when properly made the material is so finely divided that 
even if it is not thoroughly chewed it will presumably oll'cr much less 
resistance to the digestive juices than nuts hastily eaten. Xuts, and 
hence nut butters, are very rich in fat which readily becomes rancid 
and unpalatable. This is doubtless one of the reasons why nut but- 
ters are (luite commonly marketetl in jars, etc., containing small 
amounts wliich may be utilized in a short time. Tiie nut butters 
are recommended l\v vegetarians as a substitute for butter in culi- 
nary processes anil for use at the table. With persons who are not 
vegetarians they are commonly used for making sandwiches and in 
otlier ways for their agreeable flavor and for the ])leasing variety 
which they give the diet. 

Nut butter may be easily made at home. The nuts may be 
pounded in a mortar, but a mill for grinding them is much more con- 
venient and may ])e readily procured, as there are a iiunil>er of sorts 
on the market. The ])roeess of making nut butters has lieen fre- 
quently described in journals and cookery books. Either the raw 
or the roasted peanut may b(> used for making j^canut butter, but 
the roasted nut is the more satisfactory. The kernels should be freed 
from chalT and reduced to a paste in the grinding mill. Freshly 
roasted nuts are necessary, as tlmsc which have stood for a ch^y or so 
after roasting lo.se in crispness, do not grind well, and tend to chig 
the mill. Any sort of nut may be used, but experience has shown 
that it is more tliilicult to mak(> butters from the almond ur Brazil 
nut tiian from the. peanut. Blanching these nuts rec[uires cDusid- 
erabl}' more time and labor than is needed to free the peanut from 
the skin which covers the kernel, and they are also more difllcult to 
grind. N'ut butters will keep well if sealed in glass or earthernware 
jars. Tin cans also may be used, Init are not (piite as desirable. As 
might ])e exjiected, nut Ixitters do not dill'er materially in composi- 
tion from the nuts from wliich they are ground. (See table, p. 299.) 

Th(> nut butters just mentioned are entirely different from cocoanut 
butter and from cocoa butter, which are expressed and purified fats. 
These "butters" are of consideralde commercial imi)ortance and are 
used for culinaiy purposes, though ]>erhaps they are more commonly 
used in other ways. 

NUT TASTES AXl> NUT PRESEUVES. 

Pastes which are used by confectioners for candy making and in 
other ways are made from nuts with the addition of sugar. Some- 
times water and starch are added, but such admixtures are inferior 
to the nut and sugar pastes. The most common material of tliis 



306 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

sort is the aliiioiul paste, which is manufactured in large quantities 
in the United States and is also imported. It is used for making 
cakes, candies, etc., the highly ornamented cakes called "marzipan," 
so popular with the Germans, being one of tire very well-known 
almond-paste confections. 

Chestnuts preserved or candied in sirup and then dried, the niar- 
ron glace of the confectioners, are esteemed a tlelicacy and are eaten 
alone or are used in confectionery, etc. Thus prepared, they are a 
common commercial article. Much less common are the English 
walnut meats in sirup, which are manufactured in Europe and 
exported to this country in limited ([uantities. In tlie Tropics a 
thick, sweet preserve is made from cocoanut and sugar which is 
much liked locally, though those who are not familiar with it con- 
sider it very sweet and insipid. As the data in the table on page 299 
show, these ]>roducts are ricli in carliohy(h-ates, owing to the added 
sugar. 

NUT FI.OLKS AND .MEALS. 

Among nut |)rodiicts may be mentioned nut Ihiurs and meals. 
Some of these are used in large (|uantities and are made on a com- 
mercial scale, while otliers, perhaps owing to the trouble and expense 
incidental to manufacture, iind only a limited use. In general, meals 
are made from the ordinary edible nuts by blanching, thoroughly 
drying, and grinding. By using a nut mill sucli meals may be ground 
at home. .iVnalyses of some products of this character will be found 
in the talile t)n page 299. Almond meal has been on the market for a 
long time, being used as i'ooti for diabetics and for making cakes, 
etc., as well as in a number of technical ways. 

Special mention should lie made of cliestnut flour, which is on sale 
in tiie United States and is u.sed for most of the culinary purposes for 
which the fiesh nut is recommended. In Italy it constitutes a con- 
siderable part (if the diet, in some regions being extensively used for 
making a sort of bread or cake. One of the most complete studies of 
the dietetic use of chestnuts has been reported by Memmo." Accord- 
ing to the author, the chestnut often serves almost as the exclusive 
food of the peasants of Tuscany for a considerable part of the year. 
The whole nuts are eaten in a variety of ways; for instance, boiled in 
water wTthout hulling, ladled and boiled, or roasted. From the flour 
various cakes and other foods are made. Acorn meal made into a 
sort of bread with I lie addition of about 7.5 per cent of flour is a 
common article of diet in several regions, notably Und)ria and Tus- 
cany, but tlie bread is l)lack and heavy and not very j)alatable. 

The early travelers and explorers make mention of the extended 
use of nuts by the American Indians, and the custom c^f using acorns 



" Lw. cil.; .see also p. 302. 



Yearbc-..-'K U S D. p; of Aancul-u..-, 1906 



Plate XV. 







Fig. 1 .—California Indians Pounding Acorn Meal for Food. 




Fig. 2.- California Indian Leaching Acorns for Food. 



NUTS AXD THEIR USES AS FOOD. 307 

as a staple food is still kept iijx Tiie niPtliods tf iircparinji; acorns 
followed by the Indians of northern California have been described by 
P. E. Goddard" in a publication of the University of California, and 
by V. K. Chesnnt,'' formerly of tlie Department of Af;riculture. 
Briefly speakino;, the shelled luits are split, dried, and ground with a 
mortar and pestle. The sifted floiu' is placed in a hollow in the sand 
on a convenient river bank and leached to free it from the bitter prin- 
ci])les present. From the leached meal a porrid<;;e or mush is made, wliich 
to the ordinary palate is nnich imj)roYed by the addition of salt. Plate 
XV shows the way in which the nuts are pounded into flour, and 
also shows an Indian woman leaching the meal. These tyjncal Indian 
foods, when well j)re|)ared, are relished by many persons who have 
tried them, and it seems not improbal)le that improved methods of 
removing the tannin and bitter ])iinciples present in most varieties of 
acorns might result in the utilization of the ai'orn crop, which is 
fairly large and is generally wasted. 

According to Chesnut's'' investigations, th<» California l)uckey(> or 
hor.se-chestnut is also used by the Indians as a food and is leached to 
fr(>e it from p isonous or objeetional)le matters in much (he same way 
as the acorn. Many attemjits have l)een made in Europe and else- 
where to treat the fruit of theconnnon liorse-chestnut in some way so 
that it might be made wholesome and ]>alatabl(>, for it undoubtedly 
contains an abundance of nutritive material, ])articiilarly starch: but 
none of these attempts has been really succes.sful. 

The use of partly extracted peanuts and other nut meals with 
wheat and rye flour for bread making shoidd be mentioned. Such 
breads liave lieen used for patients with diabetes, but have never 
come into general use, pei'ha])s because they arc not very palatable, 
since the nuts become rancid so r(>adily. 

Xl'T CAXDIES. 

One of the most extensive u.ses of nuts is in the manufactui(> of 
candy of various sorts, such as sugared almonds, liurnt almonds, mi( 
chocolates, caramels, pinoche, nut brittle, etc. WHiile there are si)me 
differences in the process of manufacture followed in these candies, 
they all in the main consist of nuts and sugar in varying jimportions, 
with flavoring extracts, and in some instances butter and flour. 

The table on page 299 shows the composition of common soi'ts oi 
nut candy. As may be seen, the water content is low and these can- 
dies are highly concentrated foods. On account of the ailded sugar 
the carbohydrate content is high. The proportion of nuts used in 
candies varies. By assuming that the nuts furnish the bulk of the fat 

aUniv. Cal. Pubs., Aiu.'r. .Vicli. and EthnoL. 1 (1903), Xo. 1, p. 27. 

6 1'. S. Di-pt. Agr., Div. I'.i.l., Conlrib. Nat. Herlxariiun, 7 1 19021, p. :«.3. 

choc. cit.. p. 3G(j. 



308 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

in tlie candy, it is estimated that nuts constituted about 50 per cent m 
the specimens analyzed. It is perhaps well to sugp;est that nut can- 
dies and other candies which sometimes cause digestive distin-bances 
would be more satisfactory if eaten in a rational way and at tlie proper 
time. Since they are concentrated foods, they should naturally 
replace an equivalent amount of some other food material and not be 
eaten in quantity simply for their palatable flavor in addition to an 
otherwise adequate daily ration. 

Xl'T COFFEES. 

A number of colfee substitutes made from nuts have been devised 
and placed on the market, peanut coffee and acorn coffee being by far 
the most common. The nuts are parched and sometimes otherwise 
treated. Sucii coffee substitutes lack the stimulating properties of 
true coffee, and tlie infusion does not have the high nutritive value 
which is sometimes claimed for it. 

(iKEEN NUTS. 

A number of kinds of nuts are used before thev are fidly ripe, and 
are esteemed a delicacy. In California in spring the markets quite 
commonly ofl'er green almonds — tliat is, the almond picked from the 
tree while the husk is of a decided green color and easily separated 
from the soft and immature shell. The kernel, after the skin is peeled 
off, is eaten with or without salt, and is relished In' many persons. 
The price of green almonds in California markets commonly varies 
from about 20 to 35 cents per pound. Green almonds are foiuid to a 
limited extent in fancy fruit shops in eastern cities and elsewhere, 
and are perhaps purchased as much for their ornamental apj^earance 
as for tiieir palat ability. They are much more commonly used in 
Europe than in the United States. Green English walnuts and green 
hazelnuts are also eaten to a considerable extent in Europe and are 
great favorites. The nuts are gathered when the shells are fully 
matured but not thoroughly "ripe. Sometimes these green nuts are 
imported into the United States. Many who have growii uji in the 
country will recall the delicate flavor of the immature butternut and 
hickory nut and the stained fuigers which they caused. Such green 
nuts have apparently never been marketed. 

Whole green walnuts and some other nuts are also used in a quite 
immature state for ])ickle making. They are picked when still 
tender enough to be easily pierced by a large pin; then, after being 
kept in brine for a number of days, they are exposed to the sun until 
they turn black. Afterwards they are placed in jars and covered 
with hot vinegar and spices. Sometimes they are treated with dry 



NUTS AND THEIR USES AS FOOD. 3U9 

salt instead of brine liefore picl^ling. It is claimed tiiat nuts thus 
treated will blacken without l)einsj; exposed to sunliglit. Such pickled 
nuts are considered by many as a very palatal)le dish for use with 
meats and ]ioultry. Walnut catsuj) is also made from green walnuts. 

NIT OILS AND 01L-CAKI-: MKALS. 

In some parts of Europe almond oil, walnut oil, and beechnut oil 
are manufactured and prized as salad oils, and in South America 
Brazil-nut oil is used for table purposes. C'ocoanut oil is an important 
oil in the Tropics. Peanut oil finds a large technical aj)])licalion and 
is also used in large quantities as a salad oil and for culinary j^urposes. 
Oils are also made from the kernel or mil of the ])each and ii])ricot, 
but these, like uKist nut oils except those mentioned, arc asc<l for 
medicinal or technical purj)oses. 

The various nut oils, which are practically ])ure fats, have a very 
high fuel value, and, like olive oil and other oils, may constitute an 
important energy -yielding constituent of the diet. It is commonly 
assumed that, like olive oil, these oils are readily assimilated when 
properly condtined witli other food nmterials, as in salads, as '" shorten- 
ing" for various dishes, and in similar ways. 

The oil-cake meals, as the ground products I'ciiuiining after the 
expression of the nut oils are called, are nuich used as food for live 
stock and all kinds of poultry, and this is esjiecially true of th(^ ]H'anut 
and cocoanut oil cakes. It has been suggestecl that such oil-cake 
meals might be valuable dietary articles if ])ro])erly manipulated, as 
they of course contain a higher jiercentage of protein than the original 
nut. Some attempts have been nuule to thus utilize ])eanut-cake 
meal, but the results have not been very satisfactory. 

PECUNIARY ECONO.MV Ol'^ NUTS. 

The composition and dig(>stibility of nuts have been discussed in the 
foregoing i)ages, but little has been said regarding the cost of nutrients 
and energ_\' which they su])ply as compared with other and more com- 
mon food materials. The table oti page ;!1() shows the comparative 
cost of a pound of protein and 1, ()()() calories of energy when furnished 
by different nuts and nut jiroducts and some other staple foods, and 
also the amounts of nutrients and energy which 10 cents' worth of 
the.se foods would sup])ly, rating the foods at certain average |)rices 
per pound. 

The common nuts — though, with the exception of the peanut, they 
are more ex]>ensive sources of pr<jtein and energy than meat and a 
number of the common foods — may yet be considered reasonablj' 
cheap sources of nutrients and energy, and hence may be regarded 
as justifiable additions to the diet on the score of economy. For 



310 



YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



the vegetarian or fTuitarian, who looks to nuts as the chief source of 
protein in the diet, the peanut must be considered as mucli the most 
economical. As may be seen by a reference to the table, 10 cents 
will purchase more protein and energy when expended for the flours 
and meals than for any of the other foods, but it must be rememl>ered 
in this connection that these are the raw materials recjuirmg con- 
siderable preparation before they are palatable. This is not neces- 
sary witli fruits antl nuts, except in the case of tlie peanut and chest- 
nut, which are usuallj' roasted before they are considered palatable 
})y most persons, though there are those who prefer them raw. When 
considering nuts, it is readily observed that 10 cents will buy about 
the same amount of nut protein as of animal ]>rotein, except in the 
case of cheese and skim milk. If spent for peanuts, it will purchase 
more than twice the protein and six times the energy that could be 
bought for tiie same expenditure fi)r ]>orterliouse steak. 

r<riini{irij economy of nuts and n.iit pmihiiix. 



Kind of food. 



Price 

ppr 

pound. 



1 
Nuts and nut products : 1 Cents. 

.\lmonds ' '20 

Brazil nuts I 20 

Chestnuts 8 

Cocoanuts i .'i 

Hicltory nuts I 

Peanuts 7 

Pecans ' la 

Pignolias i 2.") 

Pistachios ,.i 20 

Walnuts 20 

Almond paste 40 

Peanut butter i 20 

Peanut candy 2.'> 

other foods for com- 
parison; 

Porterhouse steak 

Whole milk 

Cheddar cheese 

Wheat flour 

Beans, dried 

Potatoes 



Amount for 10 cents. 



Cost of 

one 
pound 
protein. 



Dollars. 
1.76 
2.26 
1.48 
1.16 
1..55 

.32 
2.47 

.74 

.88 
2. f.6 
.117 

.(iS 
2.42 



Cost of 

1,000 
calories 
energy. 



Cents. 
13.0 
12.6 
8.3 
2.7 
7.1 
3.6 
9.1 
8.4 
6.1 
Ki.O 
21.0 
7.1 
U.8 



25 


1.31 


22. .") 


4 


1.21 


12.0 


ir, 


. .w 


7. 5 


3 


.26 


1.8 


r, 


.22 


3.1 




1. U 


6.4 



Total 

weight 

of food 

material. 


Protein. 

1 


Pounds. 


Pounds. ' 


0..50 


0.06 


..TO 


.04 


1.2.5 


.07 


2. 0(1 


OS 


1. 11 


.00 


1.43 


.31 


.67 


.04 


.40 


.14 


.50 


.11 


.m 


.04 


or. 


.03 


.56 


.1.5 


.40 


.04 


.40 


.07 


2.50 


.OS 


.62 


.17 


3.33 


..IS 


2.00 


. 45 


5.00 


.09 



Fat. 


Carl 10- 

hy- 
dra'tes. 


Pounds. 


Pounds. 


0.14 


0.14 


.16 


.02 


.06 


.44 


.73 


.29 


.28 


.04 


.45 


.20 


.23 


.04 


.20 


.03 


.27 


.08 


.13 


.03 


.06 


.10 


.23 


.09 


.07 


.28 



Energy 



.13 
.03 
2.50 
1.19 
.74 



Calories. 

767 

789 

1,196 

3,062 

1,404 

2,767 

1,003 

1,182 

1,124 

633 

475 

1,412 

845 



444 
815 
1,330 
5,495 
3,210 
1,550 



It is of more than passing interest to note that 10 cents' worth of 
peanuts will contain al)out 4 ounces (120 grams) of protein and 
2,767 calories of energy, which is more protein and energy than is 
furnished by many rations regarded as adetjuate for a day. Although 
peanuts supi:)ly protein and energj' for a smaller sum than bread, they 
are outranked by dried beans, which, at H cents a pound, will supply 



NUTS AND THEIR USKS AS FOOD. 311 

for 10 cents over 200 grains of {)rotein and 3,200 calories of ener<jy. 
If more jjeanuts and dried beans were used by fruitarians, their diet 
would be enriched and the cost decreased. The ahnond, so much 
in favor witli fruitarians, furnisiies for 10 cents about one-fourth 
tiie protein and less than one-third the enero-y sup])lied b_v ]>eanuts. 

IIAXDI.INC AND MAHKF.TINCi NTTS. 

Within tiie last few years the trade in shelled nuts has \(>ry mark- 
edly increased, and shelled walnuts, hickory nuts, iduionds, English 
walnuts, pecans, etc., are now verj' commonly found in sho))s. The 
bidk <if the nut crop is, however, marketeil luishelled. Some of the 
unshelled nuts, notably pecans and peanuts, are very often pol- 
islied before marketing by rotating them in ra])idly revolving drums 
in such a way that the shells are worn down until they are more or 
less smooth. This method of treatment also removes any dirt and 
is supposed to make the niit more salable. It is worthy of note, 
however, that the highly |)rized, large fancy pecans are marketeil 
without such treatment. 

For shelling nuts on a commercial scale a number of ingenious 
machines have been devisetl. In order to meet the market demand 
for clean and uniforndy colored luits, many nut growers have resorted 
to the process of bleaching their ])roduct. The first attempts in this 
direction were made by sulphuring; that is, by exposing the nuts 
to sulijhiu' vapor. This treatment, though im])roving the color, 
proved decidedly injurious to the flavor of the nuts and lessened the 
keeping cpialities. At the California ex])criment station ex])eri- 
ments with bleaching solutions have been carried on and very satis- 
factory residts ha\e been obtained with a mixture of sal soila, chloriil 
of lime, and water. According to n>ports of the im|)erial department 
of agriculture of tiie West Indies," a similar jirocess has been success- 
fully used for bleaching )>eanuts. The consumer should bear in 
mind that tiie bleaching of nuts is entirely unnecessary and in no 
way increases tlieii- food value. Tiie ])rocess is cai'ried on solely for 
the purpose of impro\iiig the appearance of tht' nut and tluis com- 
manding a higher price. It will doubtless be ci>ntinued as long as 
the public is willing to be guided by appearance ratiier tlian food 
value. The term "Ideaching," as ajiplietl to nuts, nuist not be con- 
founded with tile hou.sehold term "blanching," which a])plies to the 
process of removing tlie skins from nut meats, as almonds, by immers- 
ing them for a short time in hot water. 

Vegetables and fruits exposed for sale under ordinary conditions 
may be readily contaminated with bacteria, dirt, and dust. Nuts 
sold in their shells are ]>rotected in large measure from sucii contami- 
nation, yet many careful housewives wash, m- at least wipe, the nuts 



a Imp. Dept. Agr. West Indies Pamphlet No. 4;i, n. s. 



f; 



312 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

which arc to be cracked and served in the shells, as anything which 
adheres to the shell woukl readilj^ contaminate the nuts after crack- 
ing, if all were mixed together in a dish. Shelled nuts, if exposed to 
dust in shops and markets, shouhl be washed before they are used for 
salads, etc. If exposed to damp conditions, nuts mold and decay, and 
even under favorable conditions the nut oils and pits become rancid 
on long-continued storing. In the main, however, the keeping (juali- 
ties of most nuts are excellent. Nuts should be stored in sucli a way 
that they may be free from attacks of insect enemies. When such 
precautions are not taken , ' ' wormy ' ' nuts are by no means uncommon . 

SUMMARY. 

Summarizing the foregoing data, it may be said that nuts are a • 
very concentrated food, even more so than cheese, but when ration- j; 
ally used they are well assimilated and may form a part of a well- y. 
balanced diet. Nuts are a very valuable source of protein and fat, % 
these two nutrients being the characteristic constituents of the more % 
common nuts, of which the walnut and cocoanut may be t-aken as f: 
types. In nuts like the chestnut, carbohydrates are a characteristic \- 
ct)nstituent. For most families it is untloulitedly wiser to use nuts i; 
as part of the regular diet than as a condiment or supplement to an V. 
otherwise hearty meal. t 

\'egetarians and others who use mits in place of meat should not ■;; 
depend upon them as the main food supply, but should supplement J; 
them with more bulky foods with a low content of protein and fat. k 
As a whole, nuts may be classed among the staple foods and not :■ 
simply as food accessories. At usual prices, nuts are reasonable ;.' 
sources of protein and energy. Peanuts supply protein and energy ■ 
very cheaply, even compared with such staple foods as bread and 
beans. There are a number of nut foods on the market, but it may ; 
be stated tluit tliere is little to be gained from the standpoint of food . 
value or economy' in their use, especially b}' healthy persons who ' 
are willing to masticate their food thoroughly and to use nuts m •, 
reasonal)le combinations. Unless something has been added, the 
nutritive materials in such special preparations can not be greater 
than the nuts from which they are made, though in the mechanical . 
condition or in some other way the foods may be better fitted for 
ready assimilation. Furthermore, nut butters and similar foods 
give a pleasant variety to the diet, and they are relished by many 
wjio would not care for the unprejiared nuts. 

Though less subject to contamination than many other footls, nuts 
should be handled and stored under good conditions, and especially 
should he protected from dampness and insect enemies. 

O 



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